Safety-loop for type-writing machines.



T. L. KNAPP.

SAFETY LOOP FOR TYPE WRITING MACHINES.

APPLICATION FILED FEB- 28, 1914.

Patented Dec. 8, 1914.

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FFTOE THERON L. KNAPP, OF WOODSTOCK, ILLINOIS, ASSIGNOR TO THE OLIVER- TYPEWRITER COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SAFETY-LOOP FOR TYPE-WRITING MACHINES.

Specification of Letters Patent.

Patented Dec. 8, 1914.

Application filed February 28, 1914. Serial No. 821,635.

To all whom it may concern:

Be it known that I, THERON L. KNAPP, a citizen of the United States, and a resident of Woodstock, in the county of McHenry and State of Illinois, have invented certain new and useful Improvements in Safety- Loops for Type-Writing Machines; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to an improved safety holding device for the traction cord or strand of a typewriting-machine carriage, and more particularly to a safety loop applicable for use in connection with a carriage-actuating mechanism for typewriting machines of that kind embracing a cord which forms, under normal operating conditions, the connection between the carriage and the spring-actuated barrel upon which the cord is wound and unwound during the movement of the carriage, and in which the end of said cord that is attached to the carriage is provided with retaining means whereby the cord, when disconnected from the carriage, may be connected with a retaining member on the machine sh1ft-frame. Such safety loop is designed to perform its function during the period when the cord is detached from the carriage and the latter is removed from the machine; said safety loop acting in conjunction with the retaining means to prevent the cord from be ng entirely released and the spring barrel being allowed to rotate without restraint, should the cord he accidentally or inadvertently released from such retaining member.

The features constituting the invention will be clearly understood as I proceed with the description in connection with the drawings, wherein the device 1s shown as applied to a typewritlng machlne of the kind known as the Oliver, although the features constituting the invention may be applied to machines of other lands.

In the drawingsFigure 1 1s a fragmentary top plan view of a portion of an Oliver typewriting machine showing the portions thereof embodying my invention, with parts immediately above removed; Fig. 2 is a view in vertical cross-section, taken on line 22 of Fig. 1; Fig. 3 is a detail view in perspective showing the arrangement of the device constituting my invention.

Referring to the accompanying drawings, only such portions of the machine are shown which are immediately connected with the device embodying my invention, the remainng portions of the machine corresponding in construction and operation with those found in the Oliver typewriting machine.

The machine base 10 supports upon its upper surface, and substantially at the central portion, the shift-frame 11, the same comprising a frame adapted to be shifted rearwardly and forwardly for printing upper and lower case letters, and to support the paper carriage 7 which latter is adapted to be moved from left to right upon suitable tracks that are rigidly supported upon the said shift-frame, the rear track 8 being herein shown, iFig. 2).

To the le 't and rear of the shift-frame, is mounted the spring barrel 13, comprising a fiat cylindric drum provided with upper and lower flanges 13, 13 The spring barrel is rotatably mounted in horizontal position upon the top of the machine base by means of an upright pivot bolt 14. The barrel is shown as provided with a gear wheel 15, forming part of the tension controlling mechanism for the actuating spring (not shown), which iscontained within the barrel. The rotative movement of the spring barrel is transmitted to the carriage by means of a flexible connecting member 01' cord 16 fastened to the spring barrel and wrapped around the drum portion thereof a suitable number of times, to allow the cord to be wound and unwound thereon as the carriage moves in a direction toward and away fromthe spring barrel. The free end of the cord 16 is provided with a hooked connecting member 17 adapted for engagement with a depending projection or catch 9 secured to the side plate at the right-hand end of the carriage 7. Said connecting member 17 consists, as shown, of a U-shaped piece of metal (Fig. 3) the ends of which are bent back upon themselves so as to form an upper hook 17 and a lower hook 17 The upper hook 17 normally engages the projection or catch 9 of the carriage, and the lower hook is located in a position to engage a keeper 18 onthe shift-frame. This keeper extends transversely to the path of the carriage and is provided with arms other words, it is not in use while the ma-- chine is in operation. WVhen the carriage is moved to the left, beyond its normal path of movement, in the act of removing said carriage from the machine, the lower hook 17 is engaged by the keeper 18, the upper hook 17 being simultaneously disconnected from the catch 9 of the carriage.

1 Incase the'free end of the cord 16 should be released from the'keeper by accident or through inadvertence on the part of the operator, the spring barrel'would be instantly free to rotate, accompanied by the unwinding of the spring and the disarrangement of the cord upon the spring barrel. Such a condition gives rise to considerable inconvenience in that the spring must be again adjusted to the proper tension and the cord properly replaced upon the spring barrel. *In' order to eliminate the possibility of such an'accident occurring and to obviatethe resultingloss'of time and trouble in readjusting the parts, I provide a part 20, designated as a safety loop, adapted to act, in case the hooked connecting member 17 is released from the keeper 18, to engage the said "connecting member and thereby prevent farther movementof the cord and the spring barrel. The safety loop 20 consists of a straight member, preferably in the form of a stiff rod 'or wire, loosely connected at its right-handendwith the'plate 19' and at its left-hand'end with the cord. Said member is preferably provided at its inner end with a hooked extremity 20 which engages an aperture 21 in the plate 19, although other connecting-means maybe employed. From the plate the member extends substantially parallel with the cord 16 and in the direction of the spring barrel. At its left hand end said member is provided with an open eye or loop 20 adapted to engage the cord intermediate of the keeper and the spring barrel. The said loop is so formed as to permit the same to be easily engaged with and disengaged from the cord, and is of a size surficiently small to prevent the hooked connecting' member 17 from passing therethrough. The loosecon'nection between'the safety member and the plate permits the same to conform to the lateral movements of the cord, 'andsaidsafety member'is so'light as-not'to interfere with theproper action of the cord or spring barrel.

The safety loop device described is of great advantage in securing the proper operation and maintenance of the machine by preventing the escape of the free end of the cord, which in'its absence is liable to frequently occur." The release or escape of the cord results in shock to the spring barrel, spring and adjusting mechanism, resulting in injurious strain, if not actual breakage. In addition to preventing such accidental release, the device described insures a constant tension in the spring barrel and hence all unvarying condition of operation of the machine, by-eliminating the difliculty experienced in readjusting or restoring the parts to their original condition, as is necessary whenever the release of the cord occurs.

The' features of my invention maybe variously'modified as regards the details of construction without departing from the Spirit'- ofthe invention, and for that reasonv I do not wish to be limited to the structure herein described and shown, except in so far as specifically pointed out in the claims.

I claim as my invention: 5 1. In 'a'typewriting machine, the combination of a paper carriage, a spring barrel, a keeper, a 'flexible connecting member on sald spring barrel, adapted for detachable connection withthe carriage or withthe said keeper, and a safety member provided with a loop through which said flexible connecting member freely passes, and which is adapted'to engage and retain said flexible member in case the same becomesdetached from said keeper.

'2."In a typewriting machine, the combination of a paper carriage, a spring barrel, a keeper, a flexible connecting member on said spring barrel, provided with a hooked member adapted for detachable connection either with the carriage'or with thekeep'er, and a safety member comprising a wire flexibly connected with the keeper and provided with an open loop for engagement with said flexible connecting member.

3. In a typewriting machine, the combinationof a base-frame, a shift frame, a

' paper carriage movable on said shift frame,

a'keeper attached to said shift frame, a spring barrel mounted on the base-frame, a flexible connecting member on said spring barrel, provided with a hooked member adapted for detachable connection either with the carriage or with the keeper, and a safety member loosely connected at one end with theshiftframe and engaging the said connecting member -intermediate the keeper and thespring barrel. i V 4:. In a typewriting machine, the combination of a base-frame, a shift frame, a paper carriage movable on said shift frame, a

keeperatta'ched'to the shift frame, a spring barrelmounted on the base-frame, a flexible connecting member on said springbarrel, In testimony, that I claim the foregoing 10 provided with a hooked member adapted for as my invention I afiix my signature in the detachable connection either with the carpresence of two witnesses, this 24th day of riageb or with the said keeper, (ind a safetfi February, A. D. 1914.

mem er comprlsm a wire oose connecte at one end with s aid keeper an d provided THERON at its opposite end with an open loop for Witnesses:

engagement With said flexible connecting BART C. YOUNG,

member. HAROLD W. FRAME.

copies of thin patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Wnblngton, D. G." 

